Four component objective

ABSTRACT

A four component objective for picture taking and projection comprises convex front surfaces on the first, second, and fourth component lenses in the direction of light travel. The refractive power phi 11 of the first surface of the first lens ranges between 1.5 and 2.0 while the refractive power phi 21 of the first surface of the second lens and phi 22 of the second surface of the second lens range from 1.4 to 2.4 and from -2.0 to -1.0 respectively. The refractive power phi 32 of the second surface of the third lens lies between -3.7 and -2.5.

SR OR 396499104 D United males Edwards et al. 1 Mar. 14, 1972 [54] FOURCOMPONENT OBJECTIVE FOREIGN PATENTS 0R APPLICATIONS 1 Inventors: GarryEdwards; Walter Mmdler: Erich 186,917 3/1923 Great Britain ..3so/2z3Wagner, of Midland Canada 245,820 3/l966 Austria ..3so/z23 [73]Assignee: Ernst Leltz Gmbll, Wetzlar, Germany Primary Examiner-John K.Corbin [22] Filed. July 30, 1970 A"omey Kmm & wells [21] Appl. No.:59,544

[57] ABSTRACT [30] Fords" Application Priority Dan A four componentobjective for picture taking and projection Aug. 1, 1969 Germany ..P 1939 099.9 comprises convex from Surfms 9n the first. 899999. and fourthcomponent lenses in the direction of light travel. The [52] refractivepower 1b of the first surface of the first lens ranges between 1.5 and2.0 while the refractive power rim of the first [58] surface of thesecond lens and (12,, of the second surface of the 56 R f C second lensrange from 1.4 to 2.4 and from -2.0 to l.0 I l e respectively. Therefractive power of the second surface of UNITED STATES PATENTS thethird lens lies between 3.7 and 2.5.

2,449,769 9/1948 Cox ..350/223 19 Claims, 2 Drawing Figures PatentdMarch 14, 1972 GARRY EDWARDS WALTER MANDLER ERICH WAGNER lNVEA/TORS BY)/%l ,4

BACKGROUND OF THE INVENTION The present invention relates tophotographic and/or projection objectives consisting of four singlelenses.

There are already numerous four component objectives known in the art,particularly those wherein the third lens is a diverging lens while theremaining three lenses are collecting lenses (here and in the followingthe lenses are numbered on the assumption that of a picture takingobjective the first lens faces the object, while of a projectionobjective the first lens faces the screen).

Particularly well known is a type of objective to which also theobjectives according to the invention belong wherein the firstrefracting surfaces of the first, second, and fourth lenses are convexand wherein the spacing of the third lens from the fourth is greaterthan the spacing from the second lens. It has already been undertaken toimprove upon the imaging quality of such objectives by introducingcemented surfaces of short radius of curvature.

According to another suggestion the first refractive surface of thefirst lens has to have a radius of curvature which is longer than 55percent of the focal length of the objective. Additionally, thethickness of the second lens is to be greater than 12 percent of thefocal length, while the third lens must consist of a glass having anindex of refraction 11 greater than 1.68 and an Abbe number v smallerthan 33. Objectives of this type have good imaging qualities throughoutan angular field of up to 40 as, .for example, disclosed in the US. Pat.No. 2,170,428 issued on Aug. 22, 1939 to Robert Richter of Jena/Germany,and in the corresponding German Pat. No. 724,605 which, however,discloses one embodiment in excess of the U.S. Pat. disclosure.

All known four component objectives have in common, however, that theirstate of correction, particularly with regard to the correction of thespherical zone, to the astigmatic zone and to the coma of higher order,is markedly inferior to the state of correction which can beachieved'with objectives of the so-called Gauss-type.

SUMMARY OF THE INVENTION Surprisingly it has now been discovered that itis possible to achieve an improvement of the above mentioned imagingerrors in four component lenses which renders such objectives equivalentin imaging quality to the Gauss-type objectives. According to theinvention this result is achieved by providing four surfaces out of theeight existing surfaces with an extremely high refractive power.

The introduction of surfaces of high refractive power is contrary to allprevious experience since up to now the assumption prevailed that theimaging errors caused by surfaces of high refractive power cannot becorrected. Objectives according to the invention, however, arecharacterized by the combination of the following data:

1.5 s 4a,, s 2.0

3.7 (1) g 2.5 wherein it represents the refractive power of the surfaceand the index associated with d) indicates in its first digit the numberof the lens and in its second digit the surface of this particular lens,wherein the lens and surface are both numbered in the direction of lighttravel. dz therefore, stands for the refractive power of the frontsurface of lens 1.

This principle of design may be employed throughout wide ranges of focallengths with all resulting objectives having relatively large apertures.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: FIG. 1shows a sectional view of an objective according to the invention asdisclosed hereinafter in Example 1, and

FIG. 2 shows a sectional view of an embodiment as disclosed in Example19.

DESCRIPTION OF THE FRBFERREDEMBODIMENTS- 5 In the following tables thedata of seven preferred embodiments of the invented type of objectivesare listed. The state of correction of these objectives shows aremarkable improvement over the state of correction of comparable priorart objectives.

ln the tables, r, through r. represent the radii of the varioussurfaces, while a, through a, stand for the axial thicknesses andspacings of the lenses. 1:, and v, designate the refractive index andthe Abbe number respectively of the lens glasses. o l 5 indicates therefractive power of several lens surfaces.

EXAMPLE 1 Relative aperturejZ'Z field angle 45 n, v, u r,-4|.1ss 1.191

9.62112 1.130 H4 r,-l53.450

dH-l926 -35.1461 2.05s

(If-8.0936 L736 51.4 r,-57.796 -1.z1s

,-3.o119 r I l 72.479

q-Ll554 1.10 26.: -z-asss n,-22.4142 -s.1sa -98.2123

a,-12.o4s9 1.154s 34.1 r -372.074

r-4s.41s1

wherein s is the back focal distance.

EXAMPLE 2 relative aperture 1:2 field angle 45 "4 V: 14 r,=37.s4s 1.04

10.5614 1.04s s4.4s r =l72. 102

-11.1920 r,=31.3s0 v 2.140

ausa 1.s1s4 as r 50.887 -l.313

11. 2.9764 r,=l6l.342

1.5m 1.1411 213s r =22.680

a =22.0830 -s.2s4 r,=89.04l

EXAMPLE 3 relative aperture {:2 field angle 45' n, v, a ,,=s1.ss2o rsa:10.1110 1.6940 54.5

.1,-s.9s1s 1.6134 4s.s "-49.9450 -1.s4s

3.2610 r.-zoo.4an

5314 1.1411 21.4 r.==23.4264 -s.m

11=2L90B2 r =95.2488

' 11,-: 1.5306 1.1s4s 34.1 r 4243870 '=so.so14

EXAMPLE 4 relative aperture f:2.$

field angle 27' "r e M r,-44.66l 1.524

a,=l4.3968 1.6413 55.15 r =$3.|4l 1.207

a =2.Zl49 7 283.639

a,=l.9602 1.7343 26.19 r =28.296 2.595

EXAMPLE 5 relative aperture f.'2.5 field angle 27 a,=o.i 1 r,-35.2732.043

a -2.Z22l r,=326.449

a =ZJ.3945 :95. 87

a ==4.4443 1.6713 41.64 r,,= -l65.060

EXAMPLE 6 relative aperturef:2.5 field angle 27 a =6.9l9l 1.6808 54.93r,=sss.24|

' a,=0.| l l l r,=4 .393 1.549

a,=l3.l94l 1.6413 55.15 r =53.898 1.190

a,=2.22l2 r,=5 I 8.724

a.=23.4466 r,=l0l.535

a,=$.764l 1.6734 46.62 r,==l0l.53$

EXAMPLE 7 relative aperture 122.5 field angle 27 "a r =44.66l 1.524

a,=0.l 107 r,=44.2 l 7 1.450

a,=14.3968 1.6413 55.2 r.=s3.|4| |.2o7

a.=2.2i49 r,=283.639

a,= l .9602 1.7343 26.2 r.=2s.296 4.595

a.=25.3272 r =l06.334

In the embodiments of which the data are given in the following tables aremarkable improvement over the triplet prior art long focal distanceobjectives is achieved by following the same principle of design. Thecosts of manufacture of the invented objectives remain inside the sameamounts as are required for the known triplets, owing to the employmentof most inexpeneive glasses. in addition, the overall length of theinvented objectives in shorter by about 15 percent as compared to thetriplets.

EXAMPLE 8 relative aperture f:2.5 field angle 20.5

a -7.0602 1.6413 55-2 r,-38l.63l3

iii-0.0833 r -30.8445 2.163

ra -37.2798 r,-62.8734

EXAMPLE 9 relative aperture 152.8 field angle l6.5

"r VI :4 r,=32. l 200 1.946

a,-l0.6662 1.6251 52.9 r5638. 19

(t -0.0670 rr28.6426 2.351

df3.3629 1.6734 46.6 -43.1469 -1.56l

ar2.0l l 1 1.7471 27.4 r =Z0.5977 3.621

a -Z6.3783 r =72.597$

I16-7037 1.7044 29.6 r.=-l,526.3602

EXAMPLE 10 relative aperture f:4.3 field angle l4 "r e M r,=40.384 1.653

a,-6.7204 1.6675 56.59 rp-SIODJJ 1132.156! raw-l l6.2l9

fl -1.941 1.7747 27.37 r -=27.442 2.623

EXAMPLE 1 l relative aperture f:3.4 field angle 12 "a o I! r,=32.0901.616

a.-4.5168 1.5167 63.96 r,=229.l26

a,==l2.$588 1.5167 63.96 r -'=34.S42 1.501

wherein d denotes the refractive power and the index associated with 4:indicates in its first digit the number of the lens in the direction oflight travel and its second digit refers to the lens surface also in thedirection of light travel, the objective having substantially thefollowing data:

wherein s is the back focal distance, a is the refractive index, v;, isthe Abbe number, r r, are the radii of the surfaces, a, a, are the axialthicknesses and tin, indicates the refractive power of several lenssurfaces.

2. Four component objective for picture taking and projection comprisingfour lenses of which the front refracting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the firstdo and second 4a,, lens and the rear surfaces of the second d) and third(b lens have refractive powers within the ranges given in the followingTablel.5 s lb 5 2.0

2.(r s t is 1.0

3.7 s be: s= 2 .5 wherein q: denotes the refractive power and the indexassociated with 4) idnicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

relative aperture [:2

field angle 45 a,-l0.$6l4 1.6940 54.48 r,-l72.l02

a -0.l920 's- 2.148

emiss 1.6734 46.82 r,50.887 ,3z3

liq-2.9764 =16 .342

a =l.5362 1.7471 27.38 r. =22.680 3,194

a.=22,0830 r -89.04l

a =l7.2824 1.7546 34.72 r =-1069.902

wherein s is the back focal distance, n-r. are the radii of thesurfaces, a e, are the axial thicknesses and 4.. indicates therefractive power of several lens surfaces.

3. Four component objective for picture taking and projection comprisingfour lenses of which the hunt refrscting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the first dand second 4: lens and the rear surfaces of the second it and third dilens have refractive powers within the ranges given in the followingTablel.5 s 4: s 2.0

3.7 5 41:32 -2.5 where denotes the refractive power nand the indexassociated with d: indicates in its first digit the number of the lensin the direction of light travel and its second digi refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

relatlve aperture [:2

field angle 45' n, v, 4,,

tag-5.9575 1.6734 46.]

art .5374 1.7471 27.4

cpl L5 306 1.7546 34.7

wherein s is the back focal distance, r, r, are the radii of thesurfaces, a, a, are the axial thicknesses and indicates the refractivepower of several lens surfaces.

4. Four component objective for picture taking and projection comprisingfour lenses of which the front refracting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the first dand second 45, lens and the rear surfaces of the second at and third 4:lens have refractive powers within the ranges given in the followingTable- -2.0.s 4:22 s -l.0

3.7 s 32 5 2.5 wherein} denotes the refractive power and the indexassociated with 4: indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective wherein .ris the back focal distance, r, r. are the radii of the surfaces, a, a,are the axial thicknesses and 40 indicates the refractive power ofseveral lens surfaces.

5. Four component objective for picture taking and projection comprisingfour lenses of which the front refracting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the first oand second lens and the rear surfaces of the second it, and third lenshave refractive powers within the ranges given in the following relativeaperture [:2.5 field angle I 27 "r W l| r,=37.423 1.854

a,=0.l 1 l l r,=3$.273 2.043

a,=2.222l r,=326.449

a,= l .6666 1.7617 27.37 r,=24.099 J.161

wherein s is the back focal distance, r r are the radii of the surfaces,a, a, are the axialthicknesses and 4: indicates the refractive power ofseveral lens surfaces.

6. Four component objective for picture taking an projection comprisingfour lenses of which the front refracting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the first oand second da lens and the rear surfaces of the second 4),, and third dalens have refractive powers within the ranges given in the followingTable- 1.5 s d) s 2.0

3.7 s i11 s 2.5 wherein denotes the refractive power and the index associated with 4) indicates in its first digit the number of the lens inthe direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

relative aperture f:2.$ field angle 27 wherein s is the back focaldistance, r, r, are the radii of the surfaces, a, a are the axialthicknesses and it indicates the refractive power of several lenssurfaces.

7. Four component objective for picture taking and projection comprisingfour lenses of which the front surfaces of the 10 firstda and seeondlensandtherelrmrfaeesofthe seeondda andthirdolenshaverefractivepowerswithhtlle ranges giveninthe following'l'able-.

1.5 5 ll s 2.0 1.4 s e 2.4 2.0 d) s1.0

sociated with 45 indicates in its first digit the number of the lens inthe direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

relative aperture field angle [6.5

I II, V, n r,32. l 200 1.946

erg-2.3535 r,-668.63 l 4 af-6.7037 1.7044 29.. r,-l 526.3602 .r-50.6831

wherein s is the back focal distance r, r; are the radii of thesurfaces, 0, a are the axial thicknesses and o indicates the refractivepower of several lens surfaces.

'8. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first and second 4a,, lens and the rear surfaces of the second d!and third 42,, lens have refractive powers within the ranges given inthe following Table- -7 s s2 2 wherein B denotes the refractive powerand the index associated with indicates in its first digit the number ofthe lens in the direction of light travel and its second digit refers tothe lens surface also in the direction of light travel, the objectivehaving substantially the following data:

relative aperture [-4.3 field angle 14 n, v, u

rg -l 16.219

a =l.904l 1.7747 27.37

III-22.8493

wherein .r is the back focal distance, r -r are the radii of thesurfaces, a,-a are the axial thicknesses and it indicates the refractivepower of several lens surfaces.

9. Four component objective for picture taking and projection comprisingfour lenses of which the front refracting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the firstit and second 45, lens and the rear surfaces of the second 05,, andthird do lens have refractive powers within the ranges given in thefollowing Table- 3.7 wherein it denotes the refractive power and theindex associated with d: indicates in its first digit the number of thelens in the direction of light travel and its second digit refers to thelens surface also in the direction of light travel, the objective havingsubstantially the following data:

wherein s is the back focal distance, r,-r are theradii of the surfaces,a,a are the axial thicknesses and da indicates the refractive power ofseveral lens surfaces.

10. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first 4: and second o lens and the rear surfaces of the second 4,and third qS lens have refractive powers within the ranges given in thefollowing Table- 2.0 s 4),, s-LO 3.7 s 4: s2.5 wherein 4: denotes therefractive power and the index associated with 4: indicates in its firstdigit the number of the lens in the direction of light travel and itssecond digit refers to the lens surface also in the direction of lighttravel, the objective having substantially the following data:

relative aperture [:4 field angle 10' o 0n r,=2s.ts4 1.840

a =4.S 147 l.5l87 63.96 r,=303.966

a,=0.l003 r,=2s.s7s 2.004

=9.279l 1.5[87 63.96 r,=28.204 LBSD a,=2.006$ r,=5 I 7.351

u,= l .5049 1.6942 30.95 r =20.302 3.4l9

aFlZJ708 r,=$5.620

a, =3.0098 1.5854 L80 r.=96.007

wherein s is the back focal distance, r,r are the radii of the surfaces,a,-a are the axial thicknesses and it indicates the refractive power ofseveral lens surfaces.

11. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first d) and second #2,, lens and the rear surfaces of the secondo and third (0 lens have refractive powers within the ranges given inthe following Tablel.5 s ii 5 2.0

relative aperture f:2.8 field angle l0 "0 V4- 01: r -32.779 Lsna,-0.099ii r;-3l.057 L070 l -12.4429 [.5187 63.96 -46.25; l.l2l

a L996S r.-248.654

Il -L497 1.6942 30.95 -21.2113

09228799 -szmo a,- 2.9948 1.5854 4 .110 r -l 27.199

r-ssaozi wherein s is the back focal distance, r -r, are the radii ofthe surfaces, 0 -0 are the axial thicknesses and it indicates therefractive power of several lens surfaces.

12. Four component objective for picture taking and projectioncomprising four'lcnses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first d and second 4a,, lens and the rear surfaces of the seconddi and third it lens have refractive powers within the ranges given inthe following Tablel.5 s 4: s 2.0

3.7 g 2.5 wherein 4: denotes the refractive power and the indexassociated with 4: indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

wherein s is the focal distance, r -r, are the radii of the surfaces, 8-0 are the axial thicknesses and 4: indicates the refractive power ofseveral lens surfaces.

13. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first it and second 4),, lens and the rear surfaces of the second41,, and third d lens have refractive powers within the ranges given inthe following Tablewherein it denotes the refractive power and the indexas sociated with 4: indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective wherein s'is the back focal distance, r,-r are the radii of the surfaces, a,-a arethe axial thicknesses and 11 indicates the refractive power of severallens surfaces.

14. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first d) and second lens and the rear surfaces of the second 4);:and third 42 lens have refractive powers within the ranges given in thefollowing Table- 1.4 s in $2.4

3.7 s 41 s2.5 wherein 4) denotes the refractive power and the indexassociated with 4: indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

relative aperture 124.3 field angle 8 n, v, t r,=30.695 1.689

a =9.7600 r, =6l.005

a =2.9980 1.5854 41.80 r, =60. I01

wherein s is the back focal distance, r,-r are the radii of thesurfaces, (2 a, are the axial thicknesses and dz indicates therefractive power of several lens surfaces.

15. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first 1b and second 4),, lens and the rear surfaces of the secondda and third da lens have refractive powers within the ranges given inthe following Table 1.5 s 4a,, s 2.0

5g $2.5 wherein d: denotes the refractive power and the index associatedwith 05 indicates in its first digit the number of the lens in thedirection of light travel and its second digitrefers to the.

lens surface also in the direction of light-travel, the. objectivehaving substantially the following data:

relative aperture 124.0 field angle 7 I} u r =28.203 Ila.

a,-4.5l76 1.5187 63.96 r 305.00|

a,=9.2850 1.5187 63.96 r 28.244 1.I37

a -2.0078 r,--s 6.980

wherein s is the back focal distance, r -r are the radii of thesurfaces, 0 -0 are the axial thicknesses and 4: indicates the refractivepower of several lens surfaces.

16. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first 11 and second 2 lens and the rear surfaces of the second 4:and third 4: lens have refractive powers within the ranges given in thefollowing Table- 1.5 s it s 2.0

1.4 s it s 2.4

3.7 s sz "2.5 wherein 45 denotes the refractive, power and the indexassociated with d) indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

wherein s is the back focal distance, r,-r. are the radii of thesurfaces, a -a are the axial thicknesses and 4: indicates the refractivepower of several lens surfaces.

17. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first 4a and second 45,, lens and the rear surfaces of the secondit and third 4: lens have refractive powers within the ranges given inthe following Table- 1.5 S ri 2.0

2.0 (bu s 1.0

3.7 g 32 S "2-5 wherein vb denotes the refractive power and the indexassociated with do indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

Tablel.5 s ti s 2.0 1.4 s 4hr 2.4

2.0 s 41,, s l.0

3.7 s 42 s -2.5 wherein denotes the refractive power and the indexassociated with 4') indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

relative aperture f:2.5 field angle 20.5

a,=7.0802 [.6413 55.2 =38 l .63 l 8 u,=8.3296 1.6734 46.8 r;=59.l20ll.l39

"-10:24 |.141| 21.4 -zoszoz -J.61I7

af 11.1190 r,-sz.a1s4

-uuo r1044 an zzavsss r-asma wherein s is the back focal distance, r -r.are the radii of the surfaces, a a, are the axial thicknesses and 4:indicates the refractive power of several lens surface.

19. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first 4: and second 4m lens and the rear surfaces of the secondit and third 4a,, lens have refractive powers within the ranges given inthe following Tablev 1.5 & li 2.0

1.4 s 4hr s 2.4

3.7 g 32 2-5 wherein 4: denotes the refractive power and the indexassociated with vb indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data:

surfaces, a e, are the axial thicknesses and d1 indicates the refractivepower of several lens surfaces.

' a m k =0:

1. Four component objective for picture taking and projection comprisingfour lenses of which the front refracting surfaces of the first, Second,and fourth lens are convex and wherein the front surfaces of the firstphi 11 and second phi 21 lens and the rear surfaces of the second phi 22and third phi 32 lens have refractive powers within the ranges given inthe following Table1.5 < OR = phi 11 < OR = 2.0 1.4 < OR = phi 21 < OR =2.4 -2.0 < OR = phi 22 < OR = -1.0 -3.7 < OR = phi 32 < OR = -2.5wherein phi denotes the refractive power and the index associated withphi indicates in its first digit the number of the lens in the directionof light travel and its second digit refers to the lens surface also inthe direction of light travel, the objective having substantially thefollowing data: relative aperture f:2 field angle 45* ne ve phi ii r141.155 1.791 a1 9.6282 1.7369 51.4 r2 153.450 a2 0.1926 r3 35.861 2.055a3 8.0936 1.7369 51.4 r4 57.796 - 1.275 a4 3.0779 r5 172.479 a5 1.15541.7686 26.3 r6 24.533 - 3.133 a6 22.4142 r7 98.823 a7 12.0489 1.754634.7 r8 -372.074 s'' 49.4781 wherein s'' is the back focal distance, neis the refractive index, ve is the Abbe number, r1 - r8 are the radii ofthe surfaces, a1 - a7 are the axial thicknesses and phi ii indicates therefractive power of several lens surfaces.
 2. Four component objectivefor picture taking and projection comprising four lenses of which thefront refracting surfaces of the first, second, and fourth lens areconvex and wherein the front surfaces of the first phi 11 and second phi21 lens and the rear surfaces of the second phi 22 and third phi 32 lenshave refractive powers within the ranges given in the followingTable-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 <or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5 wherein phidenotes the refractive power and the index associated with phi indicatesin its first digit the number of the lens in the direction of lighttravel and its second digit refers to the lens surface also in thedirection of light travel, the objective having substantially thefollowing data: relative aperture f:2 field angle 45* ne ve phi ii r137.848 1.834 a1 10.5614 1.6940 54.48 r2 172.102 a2 0.1920 r3 31.3502.148 a3 6.1458 1.6734 46.82 r4 50.887 - 1.323 a4 2.9764 r5 161.342 a51.5362 1.7471 27.38 r6 22.680 - 3.294 a6 22.0830 r7 89.041 a7 17.28241.7546 34.72 r8 -1069.902 s'' 45.9771 wherein s'' is the back focaldistance, r1 - r8 are the radii of the surfaces, a1- a7 are the axialthicknesses and phi ii indicates the refractive power of several lenssurfaces.
 3. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first phi 11 and second phi 21 lens and the rear surfaces of thesecond phi 22 and third phi 32 lens have refractive powers within theranges given in the following Table-1.5 < or = phi 11 < or = 2.0 1.4 <or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32< or = -2.5 where phi denotes the refractive power and the indexassociated with phi indicates in its first digit the number of the lensin the direction of light travel and its second digi refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data: relative aperture f:2 field angle 45*ne v3 phi ii r1 37.8820 1.832 a1 10.3776 1.6940 54.5 r2 190.3362 a20.1922 r3 32.1397 2.095 a3 5.9575 1.6734 46.8 r4 49.9450 - 1.348 a43.2670 r5 200.4813 a5 1.5374 1.7471 27.4 r6 23.4264 - 3.189 a6 21.9082r7 95.2488 a7 11.5306 1.7546 34.7 r8 - 424.3870 s'' 50.5074 wherein s''is the back focal distance, r1 - r8 are the radii of the surfaces, a1 -a7 are the axial thicknesses and phi 11 indicates the refractive powerof several lens surfaces.
 4. Four component objective for picture takingand projection comprising four lenses of which the front refractingsurfaces of the first, second, and fourth lens are convex and whereinthe front surfaces of the first phi 11 and second phi 21 lens and therear surfaces of the second phi 22 and third phi 32 lens have refractivepowers within the ranges given in the following Table-1.5 < or = phi 11< or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0-3.7 < or = phi 32 < or = -2.5 wherein phi denotes the refractive powerand the index associated with phi indicates in its first digit thenumber of the lens in the direction of light travel and its second digitrefers to the lens surface also in the direction of light travel, theobjective having substantially the following data: relative aperturef:2.5 field angle 27* ne ve phi ii r1 44.661 1.524 a1 6.4232 1.680854.93 r2 907.494 a2 0.1107 r3 44.217 1.450 a3 14.3968 1.6413 55.15 r453.141 - 1.207a4 2.2149 r5 - 283.639 a5 1.9602 1.7343 28.19 r6 28.296 -2.595a6 25.3272r7 106.334 a7 4.9835 1.6413 55.15 r8 77.780 s'' 58.6533wherein s'' is the back focal distance, r1 - r8 are the radii of thesurfaces, a1 - a7 are the axial thicknesses and ii indicates therefractive power of several lens surfaces.
 5. Four component objectivefor picture taking and projection comprising four lenses of which thefront refracting surfaces of the first, second, and fourth lens areconvex and wherein the front surfaces of the first phi 11 and second phi21 lens and the rear surfaces of the second phi 22 and third phi 32 lenshave refractive powers within the ranges given in the followingTable-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 <or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5 wherein phidenotes the refractive power and the index associated with phi indicatesin its first digit the number of the lens in the direction of lighttravel and its second digit refers to the lens surface also in thedirection of light travel, the objective having substantially thefollowing data: relative aperture f:2.5 field angle 27* ne ve phi ii r137.423 1.854 a1 6.6664 1.6940 54.48 r2 248.983 a2 0.1111 r3 35.273 2.043a3 8.9676 1.7206 47.69 r4 45.552 - 1.581 a4 2.2221 r5 326.449 a5 1.66661.7617 27.37 r6 24.099 - 3.161 a6 23.3945 r7 95.187a7 4.4443 1.671341.64 r8 165.060 s'' 56.4679 wherein s'' is the back focal distance,r1 - r8 are the radii of the surfaces, a1 - a7 are the axial thicknessesand phi ii indicates the refractive power of several lens surfaces. 6.Four component objective for picture taking and projection comprisingfour lenses of which the front refracting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the firstphi 11 and second phi 21 lens and the rear surfaces of the second phi 22and third phi 32 lens have refractive powers within the ranges given inthe following Table-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or= 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5wherein phi denotes the refractive power and the index associated withphi indicates in its first digit the number of the lens in the directionof light travel and its second digit refers to the lens surface also inthe direction of light travel, the objective having substantially thefollowing data: relative aperture f:2.5 field angle 27* ne ve phi ii r144.661 1.524 a1 6.4232 1.6808 54.9 r2 907.494 a2 0.1107 r3 44.217 1.450a3 14.3968 1.6413 55.2 r4 53.141 - 1.207 a4 2.2149 r5 -283.639 a5 1.96021.7343 28.2 r6 28.296 - 2.595 a6 25.3272 r7 106.334 a7 4.9835 1.641355.2 r8 -77.780 s'' 58.6533 wherein s'' is the back focal distance, r1 -r8 are the radii of the surfaces, a1 - a7 are the axial thicknesses andphi ii indicates the refractive power of several lens surfaces.
 7. Fourcomponent objective for picture taking and projection comprising fourlenses of which the front refracting surfaces of the first, second, andfourth lens are convex and wherein the front surfaces of the first phi11 and second phi 21 lens and the rear surfaces of the second phi 22 andthird phi 32 lens have refractive powers within the ranges given in thefollowing Table-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or =2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5wherein phi denotes the refractive power and the index associated withphi indicates in its first digit the number of the lens in the directionof light travel and its second digit refers to the lens surface also inthe direction of light travel, the objective having substantially thefollowing data: relative aperture f:2.8 field angle 16.5* ne ve phi iir1 32.1200 1.946 a1 10.6662 1.6251 52.9 r2 638.5319 a2 0.0670 r3 28.64282.351 a3 5.3629 1.6734 46.8 r4 43.1469 - 1.561 a4 2.3535 r5 668.6314 a52.0111 1.7471 27.4 r6 20.5977 - 3.627 r7 72.5975 a7 6.7037 1.7044 29.8r8 1526.3602 s'' 50.6831 wherein s'' is the back focal distance, r1 - r8are the radii of the surfaces, a1 - a7 are the axial thicknesses and phiii indicates the refractive power of several lens surfaces.
 8. Fourcomponent objective for picture taking and projection comprising fourlenses of which the front refracting surfaces of the first, second, andfourth lens are convex and wherein the front surfaces of the first phi11 and second phi 21 lens and the rear surfaces of the second phi 22 andthird phi 32 lens have refractive powers within the ranges given in thefollowing Table-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or =2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5wherein phi denotes the refractive power and the index associated withphi indicates in its first digit the number of the lens in the directionof light travel and its second digit refers to the lens surface also inthe direction of light travel, the objective having substantially thefollowing data: relative aperture f:4.3 field angle 14* ne ve phi ii r140.384 1.653 a1 6.7204 1.6675 50.59 r2 -510.033 a2 0.1400 r3 38.3671.685 a3 12.8808 1.6466 55.15 r4 41.767 - 1.548 a4 2.1561 r5 -116.219 a51.9041 1.7747 27.37 r6 27.442 -2.823 a6 22.8493 r7 138.645 a7 5.60031.6800 46.82 r8 -69.455 s'' 78.2068 wherein s'' is the back focaldistance, r1 - r8 are the radii of the surfaces, a1 - a7 are the axialthicknesses and phi ii indicates the refractive power of several lenssurfaces.
 9. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first phi 11 and second phi 21 lens and the rear surfaces of thesecond phi 22 and third phi 32 lens have refractive powers within theranges given in the following Table-1.5 < or = phi 11 < or = 2.0 1.4 <or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32< or = -2.5 wherein phi denotes the refractive power and the indexassociated with phi indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data: relative aperture f:2.5 field angle12* ne ve phi ii r1 38.6911.529 a1 6.4859 1.5914 61.03 r2 545.365 a20.0997 r3 37.3641.529 a3 16.1502 1.5712 55.85 r4 52.491 -1.088 a4 2.4946r5 -299.255 a5 1.4959 1.7686 26.31 r6 24.237 -3.171 a6 19.7906 r7 73.234a7 2.9917 1.6241 36.11 r8 -92.756 s'' 54.1134 wherein s'' is the backfocal distance, r1 - r8 are the radii of the surfaces, a1 - a7 are theaxial thicknesses and phi ii indicates the refractive power of severallens surfaces.
 10. Four component objective for picture taking andprojection comprising four lenses of which the front refracting surfacesof the first, second, and fourth lens are convex and wherein the frontsurfaces of the first phi 11 and second phi 21 lens and the rearsurfaces of the second phi 22 and third phi 32 lens have refractivepowers within the ranges given in the following Table-1.5 < or = phi 11< or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0-3.7 < or = phi 32 < or = -2.5 wherein phi denotes the refractive powerand the index associated with phi indicates in its first digit thenumber of the lens in the direction of light travel and its second digitrefers to the lens surface also in the direction of light travel, theobjective having substantially the following data: relative aperture f:4field angle 10* ne ve phi ii r1 28.184 1.840 a1 4.5147 1.5187 63.96 r2303.966 a2 0.1003 r3 25.8782.004 a3 9.2791 1.5187 63.96 r4 28.204 -1.839a4 2.0065 r5 -517.357 a5 1.5049 1.6942 30.95 r6 20.302 -3.419 a6 12.3708r7 55.620 a7 3.0098 1.5854 41.80 r8 -96.007 s'' 68.4689 wherein s'' isthe back focal distance, r1 - r8 are the radii of the surfaces, a1 - a7are the axial thicknesses and phi ii indicates the refractive power ofseveral lens surfaces.
 11. Four component objective for picture takingand projection comprising four lenses of which the front refractingsurfaces of the first, second, and fourth lens are convex and whereinthe front surfaces of the first phi 11 and second phi 21 lens and therear surfaces of the second phi 22 and third phi 32 lens have refractivepowers within the ranges given in the following Table-1.5 < or = phi 11< or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0-3.7 < or = phi 32 < or = -2.5 wherein phi denotes the refractive powerand the index associated with phi indicates in its first digit thenumber of the lens in the direction of light travel and its second digitrefers to the lens surface also in the direction of light travel, theobjective having substantially the following data: relative aperturef:2.8 field angle 10* ne ve phi ii r1 32.779 1.582 a1 6.9878 1.518763.96 r2 Infinity a2 0.0998 r3 31.0571.670 a3 12.4429 1.5187 63.96 r446.253 -1.121 a4 1.9965 r5 -248.654 a5 1.4974 1.6942 30.95 r6 21.283-3.262 a6 22.9799 r7 62.076 a7 2.9948 1.5854 41.80 r8 -127.799 s''55.3021 wherein s'' is the back focal distance, r1 - r8 are the radii ofthe surfaces, a1 - a7 are the axial thicknesses and phi ii indicates therefractive power of several lens surfaces.
 12. Four component objectivefor picture taking and projection comprising four lenses of which thefront refracting surfaces of the first, second, and fourth lens areconvex and wherein the front surfaces of the first phi 11 and second phi21 lens and the rear surfaces of the second phi 22 and third phi 32 lenshave refractive powers within the ranges given in the followingTable-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 <or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5 wherein phidenotes the refractive power and the index associated with phi indicatesin its first digit the number of the lens in the direction of lighttravel and its second digit refers to the lens surface also in thEdirection of light travel, the objective having substantially thefollowing data: relative aperture f:2.8 field angle 10* ne ve phi ii r131.5893 1.642 a1 6.9863 1.5187 64.0 r2 Infinity a2 0.0998 r3 31.81411.630 a3 11.5300 1.5187 64.0 r4 43.2309 -1.200 a4 2.3954 r5 -156.3477 a51.4971 1.6942 31.0 r6 21.9650 -3.160 a6 18.9835 r7 67.0252 a7 2.99411.5854 41.8 r8 -91.6156 s'' 59.5668 wherein s'' is the focal distance,r1 - r8 are the radii of the surfaces, a1 - a7 are the axial thicknessesand phi ii indicates the refractive power of several lens surfaces. 13.Four component objective for picture taking and projection comprisingfour lenses of which the front refracting surfaces of the first, second,and fourth lens are convex and wherein the front surfaces of the firstphi 11 and second phi 21 lens and the rear surfaces of the second phi 22and third phi 32 lens have refractive powers within the ranges given inthe following Table-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or= 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5wherein phi denotes the refractive power and the index associated withphi indicates in its first digit the number of the lens in the directionof light travel and its second digit refers to the lens surface also inthe direction of light travel, the objective having substantially thefollowing data: relative aperture f:2.8 field angle 8* ne ve phi ii r133.172 1.564 a1 7.0071 1.5187 63.96 r2 Infinity a2 0.1001 r3 31.2311.661 a3 12.6516 1.5187 63.96 r4 49.937 -1.039 a4 2.0020 r5 -277.429 a51.5015 1.6942 30.95 r6 21.146 -3.283 a624.9799 r7 60.094 a7 3.00311.5854 41.80 r8 -150.093 s'' 53.3337 wherein s'' is the back focaldistance, r1 - r8 are the radii of the surfaces, a1 - a7 are the axialthicknesses and phi ii indicates the refractive power of several lenssurfaces.
 14. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first phi 11 and second phi 21 lens and the rear surfaces of thesecond phi 22 and third phi 32 lens have refractive powers within theranges given in the following Table-1.5 < or = phi 11 < or = 2.0 1.4 <or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 22< or = -2.5 wherein phi denotes the refractive power and the indexassoCiated with phi indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data: relative aperture f:4.3field angle 8*ne ve phi ii r1 30.695 1.689 a1 4.4969 1.5187 63.96 r2 290.142 a2 0.0999r3 30.545 1.698 a3 11.4393 1.5187 63.96 r4 31.148 - 1.665 a4 1.9986 r5-143.227 a5 1.4990 1.7044 29.84 r6 23.894 -2.948 a6 9.7600 r7 61.005a72.9980 1.5854 41.80 r8 -60.101s'' 68.5721 wherein s'' is the back focaldistance, r1 - r8 are the radii of the surfaces, a1 - a7 are the axialthicknesses and phi ii indicates the refractive power of several lenssurfaces.
 15. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first phi 11 and second phi 21 lens and the rear surfaces of thesecond phi 22 and third phi 32 lens have refractive powers within theranges given in the following Table 1.5 < or = phi 11 < or = 2.0 1.4 <or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32< or = -2.5 wherein phi denotes the refractive power and the indexassociated with phi indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data: relative aperture f:4.0 field angle 7*ne ve phi ii r1 28.203 1.839 a1 4.5176 1.5187 63.96 r2 305.001 a2 0.1004r3 25.901 2.003 a3 9.2850 1.5187 63.96 r4 28.244 - 1.837 a4 2.0078 r5-516.980 a5 1.5059 1.6942 30.95 r6 20.313 - 3.417 a6 12.3787 r7 55.572a73.0117 1.5854 41.80 r8 -96.291 s'' 70.2337 wherein s'' is the back focaldistance, r1 - r8 are the radii of the surfaces, a1 - a7 are the axialthicknesses and phi ii indicates the refractive power of several lenssurfaces.
 16. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first phi 11 and second phi 21 lens and the rear surfaces of thesecond phi 22 and third phi 32 lens have refractive powers within theranges given in the following Table-1.5 < or = phi 11 < or = 2.0 1.4 <or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32< or = -2.5 wherein phi denotes the refractive power and the indexassociated with phi indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data: relative aperture f:4.0 field angle 6*ne ve phi ii r1 30.050 1.726 a1 4.5022 1.5187 63.96 r2 363.927 a2 0.1000r3 30.452 1.703 a3 10.3508 1.5187 63.96 r4 31.892 - 1.626 a4 2.0010 r5-141.468 a5 1.3744 1.6942 30.95 r6 24.043 - 2.887 a6 10.1405 r7 68.038a7 3.0015 1.5854 41.80 r8 -61.405 s'' 69.5493 wherein s'' is the backfocal distance, r1 - r8 are the radii of the surfaces, a1 - a7 are theaxial thicknesses and phi ii indicates the refractive power of severallens surfaces.
 17. Four component objective for picture taking andprojection comprising four lenses of which the front refracting surfacesof the first, second, and fourth lens are convex and wherein the frontsurfaces of the first phi 11 and second phi 21 lens and the rearsurfaces of the second phi 22 and third phi 32 lens have refractivepowers within the ranges given in the following Table-1.5 < or = phi 11< or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0-3.7 < or = phi 32 < or = -2.5 wherein phi denotes the refractive powerand the index associated with phi indicates in its first digit thenumber of the lens in the direction of light travel and its second digitrefers to the lens surface also in the direction of light travel, theobjective having substantially the following data: relative aperturef:2.5 field angle 27* ne ve phi ii r1 42.003 1.620 a1 6.9191 1.680854.93 r2 555.241 a2 0.1111 r3 41.393 1.549 a3 13.1941 1.6413 55.15 r453.898 -1.190 a4 2.2212 r5 -518.724 a5 1.9658 1.7617 27.37 r6 27.059 -2.815 a6 23.4466 r7 101.535 a7 5.7641 1.6734 46.82 r8 -101.535 s''55.9258 wherein s'' is the back focal distance, r1 - r8 are the radii ofthe surfaces, a1 - a7 are the axial thicknesses and phi ii indicates therefractive power of several lens surfaces.
 18. Four component objectivefor picture taking and projection comprising four lenses of which thefront refracting surfaces of the first, second, and fourth lens areconvex and wherein the front surfaces of the first phi 11 and second phi21 lens and the rear surfaces of the second phi 22 and third phi 32 lenshave refractive powers within the ranges given in the followingTable-1.5 < or = phi 11 < or = 2.0 1.4 < or = phi 21 < or = 2.4 -2.0 <or = phi 22 < or = -1.0 -3.7 < or = phi 32 < or = -2.5 wherein phidenotes the refractive power and the index associated with phi indicatesin its first digit the number of the lens in the direction of lighttravel and its second digit refers to the lens surface also in thedirection of light travel, the objective having substantially thefollowing data: relative aperture f:2.5 field angle 20.5* ne ve phi iir1 35.9214 1.785 a1 7.0802 1.6413 55.2 r2 381.6318 a2 0.0833 r3 30.84452.183 a3 8.3296 1.6734 46.8 r4 59.1201 - 1.139 a4 2.3168 r5 229.2469 a52.0824 1.7471 27.4 r6 20.3292 - 3.675 a6 37.2798 r7 62.8734 a7 7.49661.7044 29.8 r8 226.7839 s'' 36.1438 wherein s'' is the back focaldistance, r1 - r8 are the radii of the surfaces, a1 - a7 are the axialthicknesses and phi ii indicates the refractive power of several lenssurface.
 19. Four component objective for picture taking and projectioncomprising four lenses of which the front refracting surfaces of thefirst, second, and fourth lens are convex and wherein the front surfacesof the first phi 11 and second phi 21 lens and the rear surfaces of thesecond phi 22 and third phi 32 lens have refractive powers within theranges given in the following Table-1.5 < or = phi 11 < or = 2.0 1.4 <or = phi 21 < or = 2.4 -2.0 < or = phi 22 < or = -1.0 -3.7 < or = phi 32< or = -2.5 wherein phi denotes the refractive power and the indexassociated with phi indicates in its first digit the number of the lensin the direction of light travel and its second digit refers to the lenssurface also in the direction of light travel, the objective havingsubstantially the following data: relative aperture f:3.4 field angle12* ne ve phi ii r1 32.090 1.616 a1 4.5168 1.5187 63.96 r2 229.126 a20.1004 r3 32.540 1.594 a3 12.5588 1.5187 63.96 r4 34.542 - 1.501 a42.0075 r5 -203.589 a5 1.3789 1.6942 30.95 r6 23.829 - 2.913 a6 12.6369r7 60.386 a7 4.6484 1.5919 48.36 r8 -65.945 s'' 70.5338 wherein s'' isthe back focal distance, r1-r8 are the radii of the surfaces, a1-a7 arethe axial thicknesses and phi ii indicates the refractive power ofseveral lens surfaces.